USDA Develops Test Strips to Identify Poisonous Mushrooms Before You Eat One

The North American Mycological Association is a 61-year-old organization that promotes both scientific and educational activities related to mushrooms and other fungi. On its website, NAMA provides basic lesson plans for teaching kids about assorted fungi, and it even has a suggested reading list for amateur mushroom enthusiasts. It hosts an annual photo contest that recognizes the best fungi-related pics of the year. And it also has an entire section dedicated to mushroom poisonings.

The group says that, of the 10,000 different larger fungi that are found in North America, less than 100 are considered "dangerously poisonous"—but the ones that fall into that latter category can be fatal to humans and dogs that mistakenly ingest them. NAMA even has a printable poster that illustrates two of the most dangerous mushrooms, the charmingly named Death Cap (Amanita phalloides) and Destroying Angel (Amanita bisporigera), and it uses eight languages to urge people to "know their mushrooms."

Part of what makes the Death Cap so worrisome is that it looks very much like the Springtime Amanita (Amanita velosa), which is sought by mushroom foragers. While the Springtime Amanita is both harmless and delicious, its evil twin the Death Cap contains a kind of poison known as an amatoxin, which can cause liver and kidney damage. It can also straight-up kill you.

According to the U.S. Department of Agriculture's (USDA) Agricultural Research Service (ARS), the current method of testing for amatoxins are time-consuming and rely on expensive, specialized equipment. But—and this is a big but—that might soon be known as the "previous method," as ARS scientists have developed a portable test strip that can quickly and accurately detect amatoxins in a "rice grain-sized" piece of a mushroom, or they can be used to test the urine of a human or dog that may have consumed a poisonous mushroom.

Perhaps most importantly, the new test can provide either a positive or a negative result within 10 minutes.

"We developed the test primarily for mushrooms as food products. Serendipitously, it was sensitive enough to also detect the toxin in urine," ARS microbiologist Candace Bever said in a statement. "Our hope is that doctors and veterinarians will be able to quickly and confidently identify amatoxin poisoning rather than having to clinically eliminate other suspected gastrointestinal diseases first."

That's an important point. As Bevers and her team wrote, it can take between six and 24 hours for the symptoms of amatoxin poisoning to appear and, by that time, the toxins could've already caused damage to the patient's liver or kidneys.

The USDA's research was recently published in the journal Toxins. Bevers told The Counter that a company called Amatoxtest is already "in the process" of licensing this technology, and it hopes to make the test strips available for purchase later this year. In the meantime, amateur mycologists and mushroom foragers will just have to keep studying NAMA's ominous-looking warning poster.